Oil well contamination removing tool



Sept. 15, 1953 J- W. HODGES OIL WELL CONTAMINATION REMOVING TOOL Filed Dec. 20, 1949 w 4 l 2 R m. n m m m m 2 s I ay/x m V mm w I LG a v w a 5 I I 4. a J w c w. w w a v w m w 4 I. 0 4 ll m l I l 8 l 5 2 2 mm I V I4 i1 i n V k 2 ATTORNEYS Patented Sept. 15, 1953 OIL WELL CONTAMINATION REMOVING TOOL James W. Hodges, Beaumont, Tex., assignor to Sun Oil Company, Philadelphia, Pa., a. corporation of'New Jersey Applicatiqnpecember 20, 1949, Serial No. 134,011

4 Claims. 1

This invention relates to a device adapted to be lowered into an oil well casing before the tubing is set in order to remove deposits from the well which would tend to prevent the free. flow of fluid into or out of a well after the tubing has been set. In particular the device i designed to effect a series of steps in cleaning out the zone of contamination which normally exists between the sand face of an oil formation and the lower end of the casing which is in communication with the oil formation.

In the usual method for completing or preparing for production, oil, gas and salt water disposal wells, the well is of course first drilled through to the desired formation. For example, in preparing an oil well for production, the well would first be drilled to the oil formation and preferably 30 or 40 feet below the formation, in order that tools can be utilized in completing the well. After the well is drilled and the casing is positioned there-within, the casing is set usually by cementing adjacent the sand face of the oil formation. Following this, in order to provide communication with the oil formation, the casing is perforated by what is normally known as gunperforation in order to provide communication with the oil formation. In drilling the well, it is necessary to circulate a drilling mud into and out of the well as it is being drilled in order to remove the drilled out material. After the casing has been set and perforated, it is necessary to remove any drilling mud remaining in the well which is usually done by circulating water, and then a tubing string, which is of smaller diameter than the diameter of the casing, is inserted in the casing and maintained in fixed position within the casing by using what is known as apack-off or packer which is positioned above the perforations in the casing; while the upper end of the tubing will be maintained in fixed position relative to the casing by a collar positioned around the tubing.

In the zone adjacent the perforated area of the casing other contaminants, in addition to drilling mud, are found which tend to prevent the free flow of fluid into or out of the well tubing, such as, loose cement which has been deposited during the cementing operation, silt, and so forth. Various methods have been resorted to in order to remove these contaminants, but apparently no very satisfactory method has heretofore been devised since it often happens that after the Well has been completed it may produce for a short time and then the perforations become plugged and flow into or out of the formation is no longer 2 possible. Methods used heretofore to remove the contaminants are to wash them out of the well or to bail the contaminants from the well, but these methods have not been entirely effective and are time consuming.

The present invention is directed particularly to the idea of cleaning out the zone of contamination between the sand face of an oil or gas formation and the lower end of the casing, and additionally to remove any contaminants deposited on the casing wall; and the operations are carried out while the rig is in place and before completion equipment is installed within the casing, for example, before the tubing, packer, etc. are positioned within the casing. The invention practically assures that. the well will start producing and continue to produce since substantially no contaminantswill remain in the zone adjacent the perforations in the casing or on the casing wall.

Referring to the drawings:

Figure 1 is a vertical sectional view of the device with its various elements in their first position of operation withinv the well casing.

Figure 2 is a sectional view of the device with its various elements in their intermediate position of operation within the well casing.

Figure 3 is a vertical sectional view of the device with its various elements in the final position of operation within the well casing.

Since all of the figures are similar, each will have the various parts indicated by the same numerals and reference may be had to all of the drawings simultaneously.

Referring to the figures, 10. indicates the well which has been drilled, while it indicates the casing inserted into the Well having perforations l2 therein to provide communication with the producing formation which, for the purpose of explaining the invention, will be considered an oil formation indicated at 13. The tubing string is is shown as having attached thereto a hollow tubular member i5, comprising one element of the cleaning device, having at its lower end a bit or drill l6, and located immediately above the bit is an apertured area made up of a plurality of ports [1. A tubular housing or sleeve I8 is positioned about the tubular member l5 providing a space !9 therewith, and adjacent its upper end the housing is provided with a plurality of friction springs 26 which contact the casing I I and function to guide the device into the casing. The sleeve it at its lower end is provided with a resilient valve seat 2| which is apertured to permit the elongate member I5 to reciprocate therethrough. The member I5 is in effect a valve rod since when it is pulled upwardly, the bit IE will function as a valve plug to close the opening in valve seat 2|. Directly below the valve ring or seat 2] is provided an inverted cup shaped member 22 which functions as a scraping element to remove, as the device is moved into the casing, any matter accumulated on the casing wall. Directly above the valve seat 2| is provided an apertured area which is enclosed by an inflatable seal ring 23 having an enlarged groove 24 therein. Directly above the seal ring 23 are provided ports or apertures 25 through which pressure is applied to inflate the seal ring 23 to effect a seal with the casing as shown in Figures 2 and 3. The sleeve 18 at its upper end is provided with an inwardly extending flange 26 which cooperates with the joint 21 connecting the tubing 14 and inner tubular member or valve rod I to force the device into the casing.

Referring to Figures 1, 2, and 3, respectively, for the operation of the device, it will be seen in Figure 1 that the device has been lowered into the casing to locate the bit ii at a point adjacent the casing perforations l2 and that the seal ring 23 at this time is not inflated, permitting free movement of the device into the casing and the device is guided during movement by the friction springs 20. The inverted cup shaped member 22 has moved to a line just above the perforations and its movement into the casing has scraped any accumulated matter from the casing wall in order to prevent injury to the packing or sealing ring 23.

In Figure 2, the inner tubular member I5 has been raised upwardly to position the bit I6 flush with the bottom of the valve ring 21 and also to position the apertures l'l adjacent the groove 24 in the ring 23. After the bit l6 has closed the aperture in the valve ring 21, water pressure is applied to the tubing string l4 and the liquid passes out of the inner member through the apertures I! to exert pressure through the groove 25 on the seal ring 23 to in eifect inflate the ring and thereby provide a seal with the casing H. Since the valve member 2| is flexible, the pressure of the water in the tubing will also be effective to cause a more firm contact with it and the drill l6, and hence assure at this time no leakage of the water into the casing. After the sealing ring has been expanded, the outer sleeve I8 is moved upwardly forcing the sealing ring 23 upwardly to cause a suction effect and draw through the apertures l2 into the casing material from the sand face adjacent thereto. Although not shown in the drawings, it will be understood that the lower end of the casing is closed and that suction will be effected on movement upwardly of seal ring 23. The effect of raising the device is to remove all of the hydrostatic head which had existed against the sand face of the formation by virtue of the salt water or mud in the well. This creates a pressure differential which causes the formation to produce momentarily into the casing, bringing with the formation fluid any sand, cracked cement, mud, silt, and other accumulations small enough to pass through apertures [2 which might be present in the formation adjacent the sand face.

Referring to Figure 3, the pump pressure on the inner tubular member I5 has been released and the bit l6 lowered into the accumulated matter which had been pulled into the casing. Then the pumping connections at the surface of the well are manifolded to both the annulus and tubing so that liquid can be admitted to the annulus for passage through the ports 25 into the outer sleeve or housing If: and through the valve ring or seat 2| into the casing below the seal ring 23. The liquid then will intermix with the contaminants or any loose material which has been pulled into the lower end of the casing l I, and enter the inner member l5 through the apertures I! and pass to the surface through the tubing. The pressure of the liquid passing into outer sleeve l8 will maintain the seal ring expanded and cause the liquid mixture to be forced upwardly from the lower end of the casing through the apertures I1 and out of the inner tubular member I5 and well tubing M. In order to effect an agitation of the contaminants drawn into the casing the bit It can be rotated or reciprocated so that the contaminants in the lower end of the casing may more readily become intermixed with the circulated water. From the condition of the mixture of the water and contaminants, it can be determined when the accumulated matter drawn into the casing has been removed and the operation can be repeated until it appears that no contaminants are being pulled into the casing from the well formation.

I claim:

1. A device for removing fouling material from a well having a casing therein with perforations in communication with the desired well formation which comprises a housing, adapted to be moved into and out of the casing, having an open upper end, an apertured valve ring positioned within the housing adjacent its lower end, an elongate tubular member mounted for reciprocation within the housing and extending through the upper open end of the housing and the apertured valve ring, means adjacent the upper end of the tubular member to contact the housing upper end and urge the housing into the casing, a valve plug on the lower end of the tubular member to contact the apertured valve ring when the elongate tubular member is pulled upwardly, there being an apertured area in the housing above the valve ring, an inflatable seal ring secured exteriorly of the housing about said apertured area, the housing having other apertures above the seal ring for supplying pressure to inflate the seal ring and provide a seal between the housing and well casing, and the elongate tubular member having apertures immediately above the valve plug.

2. A well tool adapted to be attached to well tubing for removing from adjacent a well formation material which would interrupt the flow of fluid between the formation and well casing which comprises a housing having an opening at its upper end, an apertured valve seat adjacent the lower end of the housing, a tubular valve rod having its upper end extending through the opening in the housing upper end and its lower end extending through the apertured valve seat, means at the upper end of the valve rod to abut the housing upper end when the rod is moved downwardly, and a valve plug at the lower end of the valve rod to close the valve seat when the rod is pulled upwardly, there being an apertured area in the housing above said valve seat, an inflatable ring secured exteriorly of the housing and enclosing said apertured area, the casing having perforations above the inflatable seal ring for supplying pressure to the housing to inflate the seal ring when the valve seat is closed, the tubular valve rod having apertures above the valve plug to cooperate with the perforations in the housing to permit circulation of liquid between the valve 5 rod. and housing and scraping means at the lower end of the housing.

3. In a well having a casing therein provided with perforations positioned in communication with the desired well formation, a device for removing fouling material from the formation in order to provide free flow of fluid between the formation and the casing which comprises a tubular housing of smaller diameter than the casing adapted to be moved into the casing to be positioned in the lower portion of the casing and provide an annulus therewith, there being an apertured area in the housing extending cireumferentially thereof, a flexible seal ring positioned exteriorly of the housing about said apertured area, the housing having cooperating apertures above the apertured area which are in communication with said annulus for supplying pressure to the flexible seal ring and efiect a seal between the housing and easing, a valve ring secured within the housing below said apertured area in the housing to provide communication between the annulus and the lower portion of the casing, an elongate tubular member extending through said housing in reciprocable relation therewith, said elongate tubular member having its upper end positioned exteriorly of the housing, coupling means for securing said upper end of the tubular member to a string of tubing and to cooperate with the upper end of the housing to force the housing into the casing, a valve plug at the lower end of the elongate tubular member for cooperating with said valve ring to prevent communication between the annulus and the lower portion of the casing when the elongate tubular member is raised and the valve plug is in sealed position with the valve ring, the elongate tubular member having apertures therein positioned above and adjacent the valve plug to provide communication between the lower portion of the casing and the tubular member when the plug is lowered to unseat-ed position relative to the valve ring.

4. A device for removing fouling material from a well bore provided with a tubular casing which extends from the upper end of the well bore to have its lower end portion in communication with the well formation comprising a housing having an open upper end and a valve seat adjacent its lower end, a reciprocative tubular m mber within the casing extending from the upper end thereof through the housing and having a valve plug positioned below and in cooperative relation with said valve seat, means on the tubular member to contact the housing to urge it downwardly of the casing, a lower apertured area in the housing above the valve seat, an inflatable seal ring secured exteriorly of the housing about said lower apertured area, an upper apertured area in the housing, perforations in the reciprocative tubular member immediately above the valve plug and said valve plug cooperating with said valve seat to urge the housing upwardly of the casing.

JAMES W. HODGES.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,469,949 Parker Oct. 9, 1923 1,664,283 Boynton Mar. 27, 1928 2,156,709 Taylor May 2, 1939 2,333,372 Wright Jan. 4, 1944 2,464,669 Brown Mar. 15, 1949 2,512,801 Kinney et a1 June 27 1950 

